A SYSTEMATIC REVIEW OF LEFT ATRIAL APPENDAGE OCCLUSION FOR STROKE PREVENTION IN PATIENTS WITH NON-VALVULAR ATRIAL FIBRILLATION: EFFICACY AND SAFETY COMPARED TO ORAL ANTICOAGULANT THERAPY.

Abstract

Background: Atrial Fibrillation AF is the most common sustained arrhythmia and is associated with significant morbidity and mortality. While anticoagulation is generally an effective therapy to reduce the incidence of stroke, one in 10 individuals has a contraindication to anticoagulants. Given that in non-valvular AF (NVAF), 90% of thrombi originate from the left atrial appendage (LAA), closing the LAA using a percutaneous device has been developed to prevent AF-related stroke in high-risk patients. Nevertheless, there is limited data about the efficacy and safety of LAA occlusion (LAAO) compared to anticoagulant therapy. Methods: In this thesis, a comprehensive systematic review was done to compare LAA occlusion and anticoagulant therapy (Warfarin or NOACs) in stroke prevention for patients with NVAF. Meta-analysis was conducted to obtain a single summary estimate of stroke prevention (haemorrhagic stroke versus ischemic stroke). Results: Six studies (3 randomized control trials and 3 observational studies) were eligible which involved a total of 4891 participants with a follow-up time of 18-36 months. Compared to anticoagulant therapy, LAAO showed no significant difference in preventing ischemic stroke or systemic embolism. Procedure and device-related complications in the LAAO arm drove these outcomes. However, significant trends were seen favouring LAAO in reducing haemorrhagic stroke or major bleeding. Moreover, CV mortality showed better outcomes with LAAO in some studies. Conclusion: This thesis showed that LAAO can be effective replacement therapy for anticoagulation in preventing stroke. It may be practically useful in minimising haemorrhagic stroke and in patients with a clear contraindication to anticoagulant therapy. Physicians should consider late device-related complications including device-related thrombosis and peridevice leaks when planning for LAAO, as this can increase the risk of stroke.